Fix Ray Tracing Light Cluster debug mode (#4327)

* Remove unneeded position from input layout of light cluster

* Changelog

Co-authored-by: sebastienlagarde <[email protected]>

Author: FrancescoC-unity

com.unity.render-pipelines.high-definition/CHANGELOG.md

@@ -161,6 +161,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fixed undo of some properties on light editor.
 - Fixed null reference exception in Raytracing SSS volume component.
 - Fixed artifact appearing when diffuse and specular normal differ too much for eye shader with area lights
+- Fixed LightCluster debug view for ray tracing.
 
 ### Changed
 - Changed Window/Render Pipeline/HD Render Pipeline Wizard to Window/Rendering/HDRP Wizard

com.unity.render-pipelines.high-definition/Runtime/RenderPipeline/Raytracing/Shaders/DebugLightCluster.shader

@@ -109,7 +109,6 @@ Shader "Hidden/HDRP/DebugLightCluster"
 
             struct AttributesDefault
             {
-                float3 positionOS : POSITION;
                 UNITY_VERTEX_INPUT_INSTANCE_ID
             };
 
@@ -180,7 +179,6 @@ Shader "Hidden/HDRP/DebugLightCluster"
 
             struct AttributesDefault
             {
-                float3 positionOS : POSITION;
                 UNITY_VERTEX_INPUT_INSTANCE_ID
             };